I been trying to bleed the steering pump for a while now and with no success. yesterday the pump shaft broke off. I will put in a new one today, but would like to get some thoughts on what might have happened. The shaft twisted than sheered. It is not a clean snap.

History is:

The vehicle is a 1972 Bronco, with a 1992 Chevy 5.7L TBI in it.

I pulled a hydro boost from a 1993 3/4 Suburban and put it in, the power steering pump was new and also correct for the '93 Suburban. The steering box is what is commonly called 4X4X2 conversion (if you have an early bronco, you're probably familiar with this) I am sure the hoses are routed correctly.

I have been unable to get the system bleed out properly and I think the stress of the air, or a blockage in the system finally broke the shaft. The vehicle was never driven on the road during my attempt to bleed it.

My guess is that there is a blockage in there some where, if so how do I check for it?

I put a new PS pump in, it's not plumbed yet. Will finish it up next chance I get.

Before putting in the new pump, I disconnected the pitman arm and moved the steering wheel back and forth, there was good fluid flow from the PS box return line, this makes me think that blockage is not the issue, any other thoughts?

I been trying to bleed the steering pump for a while now and with no success. yesterday the pump shaft broke off. I will put in a new one today, but would like to get some thoughts on what might have happened. The shaft twisted than sheered. It is not a clean snap.

History is:

The vehicle is a 1972 Bronco, with a 1992 Chevy 5.7L TBI in it.

I pulled a hydro boost from a 1993 3/4 Suburban and put it in, the power steering pump was new and also correct for the '93 Suburban. The steering box is what is commonly called 4X4X2 conversion (if you have an early bronco, you're probably familiar with this) I am sure the hoses are routed correctly.

I have been unable to get the system bleed out properly and I think the stress of the air, or a blockage in the system finally broke the shaft. The vehicle was never driven on the road during my attempt to bleed it.

My guess is that there is a blockage in there some where, if so how do I check for it?

Thanks

I have done a lot of repairs in my shop on the older GM 5.7 and 6.2 diesel thay came with that hydra boost system. First I beleive there were two different steering pumps if I remember right, one with hydra boost and one with out. The second thing that I would check did it have a serpentine or v belt sometimes the difference between the two is that it may be going backwords, I know it ran a differnt direction on water pumps between the two. hope that helps.

They were both serpentine from the factory. I did remove the smog pump and the AC compressor from the engine, but had to put in a AC compressor bypass pulley for the belt to run right. I'm sure the belt is turning the right way. The pump for the hydro boost system has 2 return ports, one from the booster and one from the box.

Just before the shaft broke, I changed the belt from a 94.5" length to 93.5" so there would be proper tension. With the 94.5" belt the tensioner was at it's lowest position. I had considered this shorter belt as a possible culprit, but I'm not sure, I don't think so because the pump has been a problem since day one.

I would like to check the flow of the fluid in the system before I begin bleeding. I'm considering fill the PS reservoir and put the return from the box into a container, then turn the wheel to get the air out and crank the engine to check the flow. Any thoughts on this?

They were both serpentine from the factory. I did remove the smog pump and the AC compressor from the engine, but had to put in a AC compressor bypass pulley for the belt to run right. I'm sure the belt is turning the right way. The pump for the hydro boost system has 2 return ports, one from the booster and one from the box.

Just before the shaft broke, I changed the belt from a 94.5" length to 93.5" so there would be proper tension. With the 94.5" belt the tensioner was at it's lowest position. I had considered this shorter belt as a possible culprit, but I'm not sure, I don't think so because the pump has been a problem since day one.

I would like to check the flow of the fluid in the system before I begin bleeding. I'm considering fill the PS reservoir and put the return from the box into a container, then turn the wheel to get the air out and crank the engine to check the flow. Any thoughts on this?

Thanks

I have to think you are using the ford p/s box or rack ?? I beleive they run at a different pressure , you can get a valve that will change the amount of pressure coming out of the pump for the ford steering but may not be good for the brakes, check with Summit I had to get one for my 34 ford with a 350 chevy engine.

I have to think you are using the ford p/s box or rack ?? I beleive they run at a different pressure , you can get a valve that will change the amount of pressure coming out of the pump for the ford steering but may not be good for the brakes, check with Summit I had to get one for my 34 ford with a 350 chevy engine.

You are correct, it is a 1979 ford box with mid 80's ford worm gear. I have come across other references to these different pressures. Will the pressure affect how the system will bleed. My understand was that the higher pressure of the pump will cause the box to blow out seals and affect how it will steer.
Where does this valve go?

Edit: I do recall coming across this valve, but they were only for rack and pinion.

You are correct, it is a 1979 ford box with mid 80's ford worm gear. I have come across other references to these different pressures. Will the pressure affect how the system will bleed. My understand was that the higher pressure of the pump will cause the box to blow out seals and affect how it will steer.
Where does this valve go?

Edit: I do recall coming across this valve, but they were only for rack and pinion.

Thanks

There is a couple of different ways to go the easy way is to replace the valve, the valve is located on the back of a GM power steering pump where you screwed in the high pressure line, that 1 inch nut on the back of the pump has the pressure valve in it. I got mine from Speedway , part number 910-32918. In my case I had a GM 350 v8 and ford rack N pinion.
I would call and explain what you are doing I think they can help you .
800 979 0122

There is a couple of different ways to go the easy way is to replace the valve, the valve is located on the back of a GM power steering pump where you screwed in the high pressure line, that 1 inch nut on the back of the pump has the pressure valve in it. I got mine from Speedway , part number 910-32918. In my case I had a GM 350 v8 and ford rack N pinion.
I would call and explain what you are doing I think they can help you .
800 979 0122

did the brake pedal feel right, you are shure the lines are installed right, when you got the new pump they new you had hydra boost, you did use the bolt and washer to press the pulley on the pump, the pulley was installed to the right position on the pump, usually flush with the end of the pump, maybe you could find out what pressure the ford system uses and what the gm system uses, the pump is rotating the correct direction, the hydra boost may be bad, I hope we did not over look the obvious. good luck.

did the brake pedal feel right, you are shure the lines are installed right, when you got the new pump they new you had hydra boost, you did use the bolt and washer to press the pulley on the pump, the pulley was installed to the right position on the pump, usually flush with the end of the pump, maybe you could find out what pressure the ford system uses and what the gm system uses, the pump is rotating the correct direction, the hydra boost may be bad, I hope we did not over look the obvious. good luck.

I don't have the drive shafts in yet so I can't be sure about the brake pedal. I have the new PS pump in and took two days to bleed it. The steering and the brake pedal feel good......Almost, everything is fine unless I turn all the way to lock to lock than the PS pump wants to bog down the engine same with the brakes. The PS Pump will grown and bog down the engine if I press too hard.

I'll hook a vacuum to it today and see how that goes. I'll look into differing pressures between the two systems. I have considered the possibility of a bad hydro boost. It seems all good, but only thing I have to go on is there are no external leaks.

I don't have the drive shafts in yet so I can't be sure about the brake pedal. I have the new PS pump in and took two days to bleed it. The steering and the brake pedal feel good......Almost, everything is fine unless I turn all the way to lock to lock than the PS pump wants to bog down the engine same with the brakes. The PS Pump will grown and bog down the engine if I press too hard.

I'll hook a vacuum to it today and see how that goes. I'll look into differing pressures between the two systems. I have considered the possibility of a bad hydro boost. It seems all good, but only thing I have to go on is there are no external leaks.

Everything else is correct.

Thanks for your help.

found this todayService
The hydro-boost in not serviceable in the field. If the unit is not functioning properly, it must be replaced. The replacement process is straight forward, but bleeding can sometimes be tricky. I am offering a choice of techniques in this area. Hydro-boost brake systems are supposed to be self-bleeding, but this does not always prove to be true.

Bleed Technique 1:

Replace any hydraulic line showing external damage. Install new seals for all disconnected fittings (as required) and install an in-line power steering filter. Tighten all hose fittings to OE specifications.

Flush the entire power steering system using the vehicle manufacturer's recommended fluid. Fill pump reservoir to the proper level.

Enable the engine to allow starting. Start engine and let idle. Slowly turn steering wheel from lock-to-lock a number of times.

Turn engine off and inspect fluid level and condition. Add or remove fluid as necessary. If fluid is foaming, wait one hour then recheck level. Repeat step 5 and 6 until fluid level is correct and shows no sign of air problem.

NOTE: Many of you are aware that Ford power steering systems are very prone to air-related problems. The most effective way to remove air in these systems is to apply a vacuum to the power steering pump reservoir. This technique can be used on most power steering systems.

Bleed Technique 2:

Remove return line from hydro-boost and plug end with appropriate size plug or bolt.

Connect two- to three-foot piece of clear hose to return port on hydro-boost unit. Place end of hose into empty container at least 1 gallon in capacity.

Refill pump reservoir as necessary. Repeat step 4 until no air is seen in return line from hydro-boost.

Remove clear hose from return port and reconnect return line from pump.

Enable the engine to allow starting. Start engine and let idle. Slowly turn steering wheel from lock to lock a number of times.

Turn engine off and inspect fluid level and condition. Add or remove fluid as necessary. If fluid is foaming, wait one hour then recheck level. Repeat step 7 and 8 until fluid level is correct and shows no sign of air problem.

One more thing are you using the the master cylinder that came with the hydra boost?

Hi,
I had already come across that and had done both ways. Last night I used a variation of the # 2 procedure.
I disconnected the return line from the HB, put a clear hose on it and started the engine; I ran several quarts of fluid through it, some by turning the wheel and some by pressing the brake.

I kept a close eye on the PS pump to make sure it didn't run dry. After about an hour of this, I still saw tiny bubbles in the clear line. I think now I will try it again tonight, after letting everything settle and see how it goes.
I still had a groan in the pump and bogging engine, but only when brakes applied and wheel turned against the stops.

Other than that there is good, smooth power assist in the wheel. Still can't be sure on the brakes. I'll get the rear drums adjusted and see how the brakes work. This will take another week to get to.

Hi,
I had already come across that and had done both ways. Last night I used a variation of the # 2 procedure.
I disconnected the return line from the HB, put a clear hose on it and started the engine; I ran several quarts of fluid through it, some by turning the wheel and some by pressing the brake.

I kept a close eye on the PS pump to make sure it didn't run dry. After about an hour of this, I still saw tiny bubbles in the clear line. I think now I will try it again tonight, after letting everything settle and see how it goes.
I still had a groan in the pump and bogging engine, but only when brakes applied and wheel turned against the stops.

Other than that there is good, smooth power assist in the wheel. Still can't be sure on the brakes. I'll get the rear drums adjusted and see how the brakes work. This will take another week to get to.

After a week or so of trying to figure out what the problems are with my installation, I have learned a couple of things and I'd like to share them with the next person that may come across this thread. I did not come across any mention of several issues with this modification on the 100's of searches I did.

First of all, there are lots of sites that tell you about bleeding the steering system and different ways of doing it. The best ones I found is linked here:

I did both of the bleeding procedures out lined in this, but still had issues.

Then I tried the way I mentioned in the above thread of removing the return hose and putting in a clear line to see the bubbles, they just kept coming, so that did not solve the problem.

Today I did a vacuum bleed and that finally worked. I hooked up the vacuum, pumped it to 20 and let it sit for about 10 minutes. I did not run the engine while doing it. I did cycle the wheel and the brake pedal while the vacuum was hooked up.
I did this about 5 times. After 10 minutes, I disconnected the vacuum and started the engine and cycled the wheel and brake pedal several times, then turned off the engine and hooked up the vacuum and let it sit for another 10 minutes.
Finally there were no more bubbles. Now it all works as it should. I get the feeling that a hydro boost install goes really well for some and for others its a nightmare, I fall into the second category.

I rented a vacuum pump from Autozone and got a pipe connector and a plug from the hardware store. One end of the pipe connector was attached on the neck of the PS pump and I pulled vacuum through it. There are several sites that tell you to do a vacuum bleed and they all say to just use a plug. the problem with using just the plug is that there are notches cut into the top of the fill hole which leak air. The pipe connector worked perfectly.

After the vacuum was applied some of the fluid came up into the line going to the Vacuum pump, this was a good thing because now I could see the bubbles.

Pictures of the pipe connector and plug are here.

Another issue I found applies to the front disk brake conversion. It's a 1974 Bronco Dana 44 with 1979 Bronco/F150 disk brake knuckles. The problem here is that the wheel stops no longer do what they were designed to do, so you can turn the steering wheel way past the point of where it should stop, this was causing the bogging of the engine by over loading the pump. I have not looked into a fix for this, but now I know this is an issue and will try not to turn the wheel to full lock.

After a week or so of trying to figure out what the problems are with my installation, I have learned a couple of things and I'd like to share them with the next person that may come across this thread. I did not come across any mention of several issues with this modification on the 100's of searches I did.

First of all, there are lots of sites that tell you about bleeding the steering system and different ways of doing it. The best ones I found is linked here:

I did both of the bleeding procedures out lined in this, but still had issues.

Then I tried the way I mentioned in the above thread of removing the return hose and putting in a clear line to see the bubbles, they just kept coming, so that did not solve the problem.

Today I did a vacuum bleed and that finally worked. I hooked up the vacuum, pumped it to 20 and let it sit for about 10 minutes. I did not run the engine while doing it. I did cycle the wheel and the brake pedal while the vacuum was hooked up.
I did this about 5 times. After 10 minutes, I disconnected the vacuum and started the engine and cycled the wheel and brake pedal several times, then turned off the engine and hooked up the vacuum and let it sit for another 10 minutes.
Finally there were no more bubbles. Now it all works as it should. I get the feeling that a hydro boost install goes really well for some and for others its a nightmare, I fall into the second category.

I rented a vacuum pump from Autozone and got a pipe connector and a plug from the hardware store. One end of the pipe connector was attached on the neck of the PS pump and I pulled vacuum through it. There are several sites that tell you to do a vacuum bleed and they all say to just use a plug. the problem with using just the plug is that there are notches cut into the top of the fill hole which leak air. The pipe connector worked perfectly.

After the vacuum was applied some of the fluid came up into the line going to the Vacuum pump, this was a good thing because now I could see the bubbles.

Pictures of the pipe connector and plug are here.

Another issue I found applies to the front disk brake conversion. It's a 1974 Bronco Dana 44 with 1979 Bronco/F150 disk brake knuckles. The problem here is that the wheel stops no longer do what they were designed to do, so you can turn the steering wheel way past the point of where it should stop, this was causing the bogging of the engine by over loading the pump. I have not looked into a fix for this, but now I know this is an issue and will try not to turn the wheel to full lock.

Good luck and I hope yours goes easier.

Way to go I knew you could get it done, usually the air pocket would have moved when you turned off the engine, never thought about how you had run the hoses.

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